view scripts/polynomial/polyreduce.m @ 1025:f558749713f1

[project @ 1995-01-11 20:52:10 by jwe]
author jwe
date Wed, 11 Jan 1995 20:52:10 +0000
parents 3470f1e25a79
children bceff7ccdb79
line wrap: on
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# Copyright (C) 1995 John W. Eaton
# 
# This file is part of Octave.
# 
# Octave is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the
# Free Software Foundation; either version 2, or (at your option) any
# later version.
# 
# Octave is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
# for more details.
# 
# You should have received a copy of the GNU General Public License
# along with Octave; see the file COPYING.  If not, write to the Free
# Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.

function p = polyreduce (p)

# usage: polyreduce(c)
#
# Reduces a polynomial coefficient vector to a minimum number of terms,
# i.e. it strips off any leading zeros.
#
# SEE ALSO: poly, roots, conv, deconv, residue, filter, polyval, polyvalm,
#           polyderiv, polyinteg

# Written by Tony Richardson (amr@mpl.ucsd.edu) June 1994.

  index = find (p == 0);

  index = find (index == 1:length(index));

  if (length (index) == 0)
    return;
  endif

  if(length(p)>1)
    p = p (index (length (index))+1:length(p));
  endif

  if (length (p) == 0)
    p = 0;
  endif

endfunction